1. Field of the Invention
Aspects of the present invention relate to a composite electrolyte membrane for a fuel cell, a method of manufacturing the composite electrolyte membrane, and a fuel cell including the composite electrolyte membrane.
2. Description of the Related Art
Fuel cells are a source of future clean energy that are alternatives to fossil energy, and have high output density and high energy conversion efficiency, which means fuel cells are applicable in a vast range of fields such as in pollution-free vehicles, domestic power generating systems, mobile electronic appliances such as mobile communication devices, medical equipment, and various devices for military and aerospace uses.
A fuel cell includes a cathode, an anode, and an electrolyte membrane disposed between the cathode and the anode. In the anode, to which fuel gas is supplied, oxidation of the fuel gas takes place. In the cathode, to which oxygen is supplied, reduction reaction of oxygen occurs. Electrons generated from the cathode and anode reactions generate electricity, and collaterally generate heat and moisture.
A high-temperature fuel cell generally uses phosphoric acid as an electrolyte. Thus, such a system needs an electrolyte membrane that is able to absorb a sufficient amount of phosphoric acid and withhold it from being drawn out of the electrolyte membrane, and that has high durability. However, electrolyte membranes known so far are not satisfactory in terms of the amount of phosphoric acid they can hold and the ability to retain phosphoric acid, thereby improvement in this regard still being necessary.